Flat warp knitting machines

ABSTRACT

A flat warp knitting machine comprising two parallel endless chains mounted for continuous revolution in the same direction and at the same speed, a plurality of hooks mounted on the chains in a plane, a weft yarn layer mounted for traversal between the two chains in a plane spaced slightly from a plane in which the chains lie and adapted to engage in a plane at least one weft yarn, and means adjacent each of the chains for pressing each of the weft yarns under a respective hook of one of the chains when the weft yarn layer is adjacent the one chain, the improvement comprising adjacent each of the chains in proximity to the points of reversal of the traverse of the weft yarn layer means for retaining each weft yarn, the retaining means being stationary in the direction of movement of the chains and being mounted in a plane between the plane in which the weft yarn layer engages the weft yarns and the plane in which the chain hooks are mounted, and means adjacent each of the chains for casting off each weft yarn on the retaining means of one of the chains when the weft yarns are being fed to the hooks of the other chain.

United States Patent [191 Kemter 1 Sept. 4, 1973 FLAT WARP KNITTINGMACHINES Heinz Kemter, Karl-Marx-Stadt, Germany [75] Inventor:

[73] Assignee: Veb Wirkmaschinenbau Karl-Marx-Stadt, Karl-Marx-Stadt,Germany [22] Filed: Nov. 11, 1971 [21] Appl. No.: 197,682

3,523.432 8/1970 Vajoa et al. 66/85 A Primary ExaminerRonald FeldbaumAttorney-Albert C. Nolte et al.

[57} ABSTRACT A flat warp knitting machine comprising two parallelendless chains mounted for continuous revolution in the same directionand at the same speed, a plurality of hooks mounted on the chains in aplane, a weft yarn layer mounted for traversal between the two chains ina plane spaced slightly from a plane in which the chains lie and adaptedto engage in a plane at least one weft yarn, and means adjacent each ofthe chains for pressing each of the weft yarns under a respective hookof one of the chains when the weft yarn layer is adjacent the one chain,the improvement comprising adjacent each of the chains in proximity tothe points of reversal of the traverse of the weft yarn layer means forretaining each weft yarn, the retaining means being stationary in thedirection of movement of the chains and being mounted in a plane betweenthe plane in which the weft yarn layer engages the weft yarns and theplane in which the chain hooks are mounted, and means adjacent each ofthe chains for casting off each weft yarn on the retaining means of oneof the chains when the weft yarns are being fed to the hooks of theother chain.

6 Claims, 15 Drawing Figures minnow 4 ma 3756043 sum s 0? 5 TE. 12A.

FLAT WARP KNITTING MACHINES The invention relates to improvements in aflat warp knitting machine, particularly a sewing knitting or Malimachine, having a weft yarn layer moving back and forth parallel to thestitch forming line and arranged behind the stitch forming line, andhaving two constantly revolving transfer chains leading to the stitchforming line, which chains are arranged under the weft yarn layer andprovided with hooks in which at least one weft yarn .can be engaged bymeans of the weft yarn layer, weft yarn being pressed temporarily underthe hooks of the transfer chains at the ends of traverse of the weftyarn layer.

A known warp knitting machine, particularly a sewing knitting machine ofthis type, serves for the production of a weft-warp knitting in whichthe wefts serve as the base and are woven between the sinker or needlestitches of the warp knitting. The wefts are formed by a group of weftyarns.

Also known is a similar warp knitting machine which can be considered asewing knitting machine, which processes as a base a non-woven fabricwhich is fed to the stitch forming line together with a single weft yarnplaced above and/or under it. This single weft yarn can be used for theproduction of patterns.

Due to the continuous drive of the transfer chains feeding the wefts tothe stitch forming line, these machines are characterized by particularsimplicity. In addition, the resultant working speed of the machine isconsiderable.

A disadvantage, however, is that the weft yarns can be engaged by theconstantly revolving transfer chains principally only in zig-zag form,because the transfer chain carrying the weft yarns continues to runwhile the weft yarn layer moves toward the opposite transfer chain.

It is an object of the invention to provide a warp knitting machine,particularly a sewing knitting machine of the above-mentioned type, onwhich a textile fabric having wefts can be produced which extendaccording to the pattern of conventional weft-warp knittings in a rightangle to the longitudinal axis of the fabric and which are, therefore,so-called parallel wefts.

It is a more specific object of the invention to engage every weft intwo transfer chain hooks which oppose each other on a line extending atleast substantially perpendicularly to the transfer chains.

Other objects and advantages of the invention will become apparent fromthe following description of the invention.

According to the invention, means for retaining each weft yarn isarranged at both reversing points of the weft yarn layer between theyarn delivery line of the weft yarn layer and the transfer chain hooks,extends in the same direction as the hooks and is immovable in thedirection of motion of the transfer chains. By means of this retainingmeans, a length of weft yarn between the transfer chain hooks and thedelivery point of the weft yarn layer can be retained alternately at theends of traverse of the weft yarn layer. By means likewise provided atthe two reversing points of the weft yarn layer and in association withthe retaining means, the

length of the weft yarn retained by the retaining means on one side canbe cast off alternately onto the adjacent transfer chain hook, when theweft yarn layer feeds the weft yarn to the hook of the transfer chain ofthe other side.

The retaining means are preferably provided with hooks extending towardthe hooks of the transfer chains.

The cast-off means consist preferably of raisable and lowerable presserswhich are held by springs in their upper inoperative position and whichcan be lowered by solenoids into their operating position. The loweringof the cast-off means into the operating positions can be started bymeans of the weft yarn layer. It is advisable to arrange the cast-offmeans on swivel arms and to turn them laterally to the outside by meansof the weft yarn layer when the pressers are not in use.

The means according to the invention for parallelizing the wefts arecharacterized by particular simplicity which ensures great reliability.This is due primarily to the fact that the retaining means arestationary.

The cast-off means cooperating with the retaining means must be movable,but it is only necessary that they be set in motion at a certain time.To this end the weft yarn layer can act at the same time as an impulsetransmitter, so that no special control means are required.

The invention will now be further described by reference to two specificembodiments thereof as illustrated in the drawings in which:

FIG. 1 is a partly schematic isometric view of a weft layer of a sewingknitting machine for the production of a weft-warp knitting the base ofwhich consists of parallel wefts;

FIG. 2 is a partly schematic isometric view of a weft yarn layer of asewing knitting machine for the production of a weft-warp knitting thebase of which consists of overlapping zig-zag wefts and of pattern weftswhich are parallel wefts;

FIG. 3 is a detail isometric view of the weft yarn layer of FIG. 1 withthe pressers which bring the weft yarns under the hooks of the transferchains;

FIG. 4 is a detail isometric view of the means for controlling thepressers of FIG. 3;

FIG. 5 is a partly schematic isometric view of the transfer of the weftsto the retaining means on the right side of the machine;

FIG. 6 is a simplified elevation view in the direction of arrow VI ofFIG. 5; FIG. 7 corresponds to FIG. 5 but illustrates the start of thedeflection of the weft yarns;

FIG. 8 is a simplified elevation view in the direction of arrow VIII ofFIG. 7;

FIG. 9 corresponds to FIGS. 5 and 7 but illustrates the end of thedeflection of the weft yarns;

FIG. 10 is a simplified elevation view in the direction of arrow X ofFIG. 9;

FIG. 11 is a partly schematic isometric view of the transfer of the weftyarns at the retaining means on the left side of the machine withsimultaneous use of the presser associated with the retaining means onthe right side of the machine;

FIG. 12 is a partly schematic isometric view of the presser with itsdriving means associated with the retaining means on the left side ofthe machine;

FIG. 13 is a partly schematic front elevation of the two pressersassociated with the retaining means in cooperation with the weft yarnlayer;

FIG. 14 is a partly schematic plan view of the front side of a weft-warpknitting formed with the weft yarn layer according to FIG. 2 andprovided with pattern wefts on the front side; and

FIG. 15 is a partly schematic plan view of the back of a similarweft-warp knitting with pattern wefts on both sides.

According to FIG. 1, the weft yarns 1 are engaged alternately by meansof the weft yarn layer 2 in the hooks 3 of two endless transfer chains 4and 5.

The weft yarn layer 2 consists of a carriage which has two side plates 6and 7 and a perforated bar 8 forming the yarn delivery line. Struts 9and 10, along with the perforated bar 8, connect the side plates 6 and 7to each other.

The weft yarn layer 2 is guided on rods 11 and is moved back and forthby means of a chain 12 parallel to the stitch forming line 13 (indicatedby broken line) of the machine. The two transfer chains 4 and lead tothe stitch forming line 13 behind which is the weft yarn layer 2 whichis arranged above the transfer chains 4 and 5. The hooks 3 of thetransfer chains 4 and 5 point upward.

As can be seen from FIGS. 3 and 4, the weft yarn layer 2 is alsoprovided with two alternately raisable and lowerable pressers l4 and 15,the function of which is to press the weft yarn layer 2 temporarilyunder the hooks 3 of the respective transfer chain 4 or 5 at therespective ends of traverse of the weft yarn layer 2, so that the weftyarns 1 cross the shafts of the hooks 3 of the respective transfer chain4 or 5 between the respective presser 14 or 15 and the perforated bar 8.This assures a satisfactory transfer of the weft yarns l to the hooks 3of the respective transfer chain 4 or 5.

In the case of FIGS. 3 and 4 the weft yarn layer 2 is at its rightmoving end, at which the left presser 14 is effective.

The pressure 14 and 15 are suspended at both ends on rocker arms 17which are secured on a shaft 18 mounted in the side plates 6 and 7. Toeach rocker arm 17 are articulated two arms 16 to the other ends ofwhich is articulated an arm 19 to form a parallelogram.

On the front rocker arm 17 (not shown) are secured two bolts 20 and 21which cooperate with stop cams 22 (FIG. 4). A cam 22 is arranged on eachmachine side. The stop cams 22 are carried each by a sleeve 23 which issecured against rotation and arranged at the front rod 11.

The weft yarn layer of FIG. 1 is provided for the production of aweft-warp knitting the base of which, consisting of the weft yarns 1, isthus woven between the needle and sinker stitches of the warp knitting,the wefts being so-called parallel wefts. In order to make thispossible, a respective retaining means 24 and 25 is provided on eachmachine side. The retaining means 24 and 25 are arranged between theperforated bar 8 and the hooks 3 of the transfer chains 4 and 5, asshown on the right hand looper 25 in FIG. 3. The retaining means 24 and25 are immovable at least in the direction of motion of the transferchains 4 and 5 and have books 26 directed toward the hooks 3 of thetransfer chains 4 and 5. The shafts of the hooks 26 are, therefore,so-to-speak crossed by the weft yarns 1 at the reversing points of theweft yarn layer 2.

When the weft yarn layer moves, for example, into its right hand endposition, the weft yarns 1, bent upwardly, are inserted by means of thepresser 14 between a hook 3 of the transfer chain 5 and a hook 26 of theretaining means 25 (FIGS. 5 and 6). Since the retaining means 25 standsstill while the transfer chains 4 and 5 move toward the stitch formingline, the hooks 26 of the retaining means 25 retain the weft yarns Iover a yarn length 27 between the perforated bar 8 and the hooks 3 ofthe transfer chain 5 and deflect the weft yarns 1 in this wayincreasingly to the rear, as can be seen from FIGS. 7 to 10.

The same process takes place between the hooks 26 of the left handretaining means 24 and the hooks 3 of the left transfer chain 4 duringthe leftward motion of the weft yarn layer 2.

The weft yarns 1 are cast off from the retaining means 24 and 25 bymeans of pressers 28 and 29, of which one is arranged on each machineside (FIGS. 1 and 13). As can be seen particularly from FIG. 12, thepressers 28 and 29 can be raised and lowered, and they are secured forthis purpose to the bottom end of a bar 30 which is held in its upperposition by means of a tension spring 31. The lowering of the pressers28 and 29 is effected by means of a solenoid, the core 32a of which issurrounded by a coil 32 and secured at the upper end of the bar 30. Thecoils 32 of the pressers 28 and 29 at the respective machine sides areenergized alternately. According to FIG. 13, respective stationarycontacts 33 and 34 are provided to this end for each coil 32. Twoadditional contacts 35 and 36 are arranged on the weft yarn layer 2.

In FIG. 13, the weft yarn layer 2 is in its left end position. Then thecontacts 33, 35 are closed activating the coil 32 of the right handpresser 29 so that the presser 29 descends.

The lowering of the left hand presser 28 is effected by the contacts 36and 34.

It can thus be seen that the yarn length 27 is cast off from the righthand retaining means 25 to the hooks 3 of the right hand transfer chain5 by means of the right hand presser 29 when the weft yarn layer 2 feedsthe weft yarns 1 to the hooks 3 of the left hand transfer chain 4 (FIG.11).

Conversely, the yarn length 27 is cast off from the left hand retainingmeans 24 to the hooks 3 of the left hand transfer chain 4 when the weftyarn layer 2 feeds the weft yarns 1 to the hooks 3 of the right handtransfer chain 5.

The offering of the weft yarns 1 to the hooks 3 of the transfer chains 4or 5 of one machine side thus coincides with the casting off of the yarnlength 27 to the hooks 3 of the transfer chains 4 or 5 of the othermachine side, which means that each weft yarn 1 is engaged by twotransfer chain hooks which oppose each other in a line which extends atleast substantially perpendicularly to the transfer chains 4 and 5.

The two pressers 28 and 29 must not be in the way of the weft yarn layer2 when the latter moves into its two end positions. To this end thepressers 28 and 29 can be lifted out by an appropriate amount. in orderto make this unnecessary, the pressers 28 and 29 are provided on arms 37and 38 which can be turned about axes 39 extending parallel to thetransfer chains 4 and 5 (FIGS. 1, l2 and 13). The inner rest position ofeach of the arms 37 and 38 is limited by respective thumbs 40. Thedeflection of the arms 37 and 38 is effected alternately by means of theweft yarn layer 2, which presses the arm 37 or 38 to the outside bymeans of the respective strut 9 or 10.

The invention is not limited to the production of a weft-warp knittingwith parallel wefts as a base. It is also possible, for example, toproduce with the invention a textile fabric which is provided withparallel pattern wefts. The base of the textile fabric can consist inthis case, for example, likewise of wefts but alternatively of anon-woven fabric or the like. If the base of the textile fabric isformed of wefts, these can be, according to the invention, eitherparallel wefts or wefts overlapping in zig-zag form according to GermanPatent l,059,608. The production of the last-mentioned textile fabric ispossible with the embodiment of FIG. 2. To this end the perforated bar 8of the weft yarn layer 2 is designed for guiding two groups of weftyarns. The rear group 41 of weft yarns forms the base in the weft-warpknitting to be produced. The weft yarns of the group 41 are alternatelyengaged in known manner in the hooks 3 of the two transfer chains 4 and5. The front group 42 of weft yarns, however, serves for the formationof the pattern and its weft yarns are laid by means of the invention asparallel wefts. Only for the group 42 is the machine, therefore,provided with the retaining means 24 and 25 and the pressers 28 and 29.

The construction of such a weft-warp knitting is illustrated in FIG. 14.

Since the pattern group 42 of weft yarns is guided in the perforated bar8 ahead of the group 41 forming the base, the pattern wefts 42 lie onthe front side of the base wefts 41. Similarly, the pattern group 42 ofweft yarns could also be fed into the perforated bar 8 behind the group41 forming the base in which case the pattern group 42 comes to lie onthe back of the base wefts 41. It is even possible to feed two patterngroups into the perforated bar 8 respectively in front of and behind thebase weft group 41. The result is then a weft-warp knitting as shown inFIG. 15. The base wefts 41 are arranged in this case between the patternweft group 42 and the pattern weft group 43.

The invention also offers the possibility of making use of the pressers28 and 29 independent in time of the feeding of the weft threads to thehooks 3 of the transfer chains 4 and 5. In this case diagonal wefts canbe produced, the angle of which differs from the angle of the base weftgroup 41.

What is claimed is:

1. In a flat warp knitting machine comprising two parallel endlesschains mounted for continuous revolution in the same direction and atthe same speed, a plurality of hooks mounted on the chains in a plane, aweft yarn layer mounted for traversal between the two chains in a planespaced slightly from a plane in which the chains lie and adapted toengage at least one weft yarn and lay said at least one weft yarnbetween said chains in a plane parallel to the plane of traversal of theweft yarn layer, and means adjacent each of said chains for pressingeach of said weft yarns under a respective hook of one of said chainswhen the weft yarn layer is adjacent said one chain, the improvementcomprising adjacent each of the chains in proximity to the points ofreversal of the traverse of the weft yarn layer means for looping eachweft yarn, said looping means being stationary in the direction ofmovement of the chains and each including means for retaining one of theweft yarns, each of said retaining means being positioned, when the weftyarn layer reaches the point of reversal in proximity to the retainingmeans, in a plane between the plane in which the weft yarn layer laysthe weft yarns and the plane in which the chain hooks are mounted, andmeans adjacent each of said chains for casting off each weft yarn on theretaining means of one of said chains when the weft yarns are being fedto the hooks of the other transfer chain.

2. A machine according to claim 1, in which the retaining means comprisehooks and the hooks of the retaining means and the hooks of the chainsare oriented with the free ends thereof in mutual opposition.

3. A machine according to claim 2, in which the casting off meanscomprise means for pressing the weft yarns adjacent the points ofengagement thereof by the hooks of the retaining means so as to urge theweft yarns out of engagement with the hooks of the retaining means.

4. A machine according to claim 3, in which each of said casting offmeans further includes a spring for holding the pressing means thereofout of engagement with the weft yarns and a solenoid operativelyconnected to the pressing means of each of the casting off means formoving the pressing means into engagement with the weft yarns uponactuation of the solenoid.

5. A machine according to claim 4, further comprising means foractuating the solenoid, a part of said actuating means being carried bythe weft yarn layer.

6. A machine according to claim 5, in which the pressing means of eachof the casting off means is mounted on a respective arm pivotallymounted for rotation in a plane transverse to the plane of the chainsand the arm is so located relative to the weft yarn layer as to beengaged by the weft yarn layer at the ends of the traversal path of theweft yarn layer and thereby be pushed out of the way.

1. In a flat warp knitting machine comprising two parallel endlesschains mounted for continuous revolution in the same direction and atthe same speed, a plurality of hooks mounted on the chains in a plane, aweft yarn layer mounted for traversal between the two chains in a planespaced slightly from a plane in which the chains lie and adapted toengage at least one weft yarn and lay said at least one weft yarnbetween said chains in a plane parallel to the plane of traversal of theweft yarn layer, and means adjacent each of said chains for pressingeach of said weft yarns under a respective hook of one of said chainswhen the weft yarn layer is adjacent said one chain, the improvementcomprising adjacent each of the chains in proximity to the points ofreversal of the traverse of the weft yarn layer means for looping eachweft yarn, said looping means being stationary in the direction ofmovement of the chains and each including means for retaining one of theweft yarns, each of said retaining means being positioned, when the weftyarn layer reaches the point of reversal in proximity to the retainingmeans, in a plane between the plane in which the weft yarn layer laysthe weft yarns and the plane in which the chain hooks are mounted, andmeans adjacent each of said chains for casting off each weft yarn on theretaining means of one of said chains when the weft yarns are being fedto the hooks of the other transfer chain.
 2. A machine according toclaim 1, in which the retaining means comprise hooks and the hooks ofthe retaining means and the hooks of the chains are oriented with thefree ends thereof in mutual opposition.
 3. A machine according to claim2, in which the casting off means comprise means for pressing the weftyarns adjacent the points of engagement thereof by the hooks of theretaining means so as to urge the weft yarns out of engagement with thehooks of the retaining means.
 4. A machine according to claim 3, inwhich each of said casting off means further includes a spring forholding the pressing means thereof out of engagement with the weft yarnsand a solenoid operatively connected to the pressing means of each ofthe casting off means for moving the pressing means into engagement withthe weft yarns upon actuation of the solenoid.
 5. A machine according toclaim 4, further comprising means for actuating the solenoid, a part ofsaid actuating means being carried by the weft yarn layer.
 6. A machineaccording to claim 5, in which the pressing means of each of the castingoff means is mounted on a respective arm pivotally mounted for rotationin a plane transverse to the plane of the chains and the arm is solocated relative to the weft yarn layer as to be engaged by the weftyarn layer at the ends of the traversal path of the weft yarn layer andthereby be pushed out of the way.